1. Field of the Invention
The present invention relates to a photoelectric conversion apparatus and an imaging system including the same.
2. Description of the Related Art
As typical kinds of photoelectric conversion apparatuses used for digital cameras, CCD type and MOS type photoelectric conversion apparatuses are cited. A photoelectric conversion apparatus has a pixel region in which pixels each including one photoelectric conversion element such as a photodiode are arranged. In the photoelectric conversion apparatuses, the number of pixels has been increased, and the countermeasures against leaked light incident in adjacent pixel (cross-talk) which can be caused by the increased number of pixels are studied. For example, against the leaked light incident in adjacent pixel when the light is incident with a large incident angle, shielding the light passing through the upper portion of a floating diffusion region, for example, is conceivable in MOS type photoelectric conversion apparatus.
Japanese Patent Application Laid-Open No. 2005-317581 discloses a construction configured to provide a large width portion in the wiring for driving pixels. By the large width portion, light shielding of the floating diffusion region (hereinafter, described as an FD region) appears to be performed.
However, in the construction of Japanese Patent Application Laid-Open No. 2005-317581, the wiring for driving pixels, namely, the wiring with the fixed potential is arranged on the upper portion of the FD region. Accordingly, the capacity of the FD region increases due to the capacity which occurs between the FD region and the wiring layer having the large width portion.
Here, in order to prevent increase in the capacity of the FD region, a method is conceivable, in which the wiring layer having the large width portion of Japanese Patent Application Laid-Open No. 2005-317581 is not electrically fixed. However, since a metal layer which is not electrically fixed is used, the metal layer may vary by being influenced by electric variation of the FD region, and propagate the electric variation to the other FD regions to cause electric cross-talk.
Thus, it is an object of the present invention to provide a photoelectric conversion apparatus capable of reducing optical cross-talk while suppressing increase in capacity of an FD region and increase in electric cross-talk of the FD region.